2 (1/4-inch-thick) slices red onion, separated into rings
1/4 cup fat-free mayonnaise
2 tablespoons chopped fresh basil
1/4 teaspoon freshly ground black pepper
4 (1 1/2-ounce) slices sourdough bread
2/3 cup bottled roasted red bell peppers
2 (1-ounce) slices provolone cheese
How to Make It
Heat olive oil in a large nonstick skillet over medium heat. Add mushrooms and onion; cover and cook 7 minutes or until onion is tender, stirring occasionally. Remove from heat; cool.
Combine the mayonnaise, basil, and black pepper. Spread 1 tablespoon mayonnaise mixture on each bread slice; layer each of 2 slices with 1/3 cup bell peppers, 1/2 cup mushroom mixture, and 1 slice of cheese. Top with remaining bread slices. Cut each sandwich in half.